Function setId

chapter24/docs/d3-graphviz.js:1044–1047

(datum, parentData)

      }
    }
    function setId(datum, parentData) {
      var id = (parentData ? parentData.id + '.' : '') + datum.key;
      datum.id = id;
    }
    function addToDictionary(datum) {
      dictionary[datum.id] = datum;
    }